This invention relates to a mechanical winch, and more particularly, to a mechanical winch which includes a mechanism for locking the winch reel to permit rotation only in either a clockwise or counterclockwise rotational mode and for free wheeling release of the winch from either mode.
Typically, a winch includes a reel about which a cable or strap is wrapped. The reel is usually mounted in a bracket and a spur gear is incorporated in one of the flanges of the reel. The spur gear is driven either directly or through a gear train by other spur gears to provide for a mechanical advantage upon rotation of a drive handle shaft. Mechanical winches operable by manual or motor rotation of the drive shaft handle have been utilized for many decades for the purpose of pulling and winding a strap or cable onto the reel thereby lifting and moving various loads.
Typically, a locking pawl is provided to restrict rotation of the gear train or gears in one direction, either clockwise or counterclockwise. Thus, upon rotating the winch in a desired direction in order to take up cable, for example, against a load, the pawl acts to maintain the reel in position and to preclude release of the cable or strap, as the case may be.
It is a desirable feature of a mechanical winch of this type to be able to choose to take up strap or cable by turning the crank handle (and thus the reel) clockwise or alternately counterclockwise depending on the particular use of the winch. It is also desirable to be able to release strap or cable by free wheeling the winch drum or reel.
These capabilities have, to date, been accomplished by a winch construction wherein a locking pawl can be positioned to preclude either clockwise or counterclockwise movement or positioned at a third or neutral position where the locking pawl does not engage the gear train or gears, and the reel then becomes free wheeling. However, once the choice is made which direction the crank handle (or reel) will be turned to take up strap or cable, one of the two locking positions of the pawl becomes useless and serves only to create unnecessary operator confusion, and the potential for accidental engagement and/or unnecessary noise during fee wheeling.
Thus, there has remained the need to develop a reversible pawl construction which is simplified by having only two positions (locked and free wheeling) which can be easily reversed to allow for locking when cranking the handle clockwise or alternately to allow for locking when cranking the handle counterclockwise. It is further desirable to have a winch with fewer parts and simplified construction.